Chevrolet 10 Series 1970, Service Manual

Page: 64 / 671

HEATER AND AIR CONDITIONING 1A-34
TEMPERATURE
O U T L E T
DEFROSTER
OUTLET SELECTOR
CABLE
DEFROSTER
CABLE
F ig . 4 3 —A ir C o n d itio n in g C o n tro ls
3. Rem ove retaining clamp s crew and loosen P O A valve
outlet pipe clam p mounting screw .
4. R em ove P O A valve in let and outlet connections and
rem o ve P O A valve. Cap the open tubes.
5. R em ove clamp fro m P O A valve.
Installation
1. A ssem b le clamp on P O A va lve and connect inlet
and outlet connections using new " O " ring seals
coated with clean r e frig e ra tio n oil.
2. Secure P O A va lve clamp and outlet line clamp.
3. Connect the evaporator o il bleed line and the ex­
pansion va lve equalizing line to the P O A va lve using
new " O " ring seals coated with clean re frig e ra tio n
oil.
4. Connect battery ground cable. Evacuate and charge
the system .
CONTROL ASSEMBLY
Removal (Fig. 4 3 )
1. Disconnect battery ground cable.
2. Rem ove the screw s in the lo w er lip of the dash which
attach the control assem bly bracket to the dash.
3. M ove the unit toward the fron t of the veh icle and
lo w e r it.
4. Disconnect the b low er harness connector and illu m i­
nating lamp sockets. Rem ove the b low er switch and
mounting bracket. R em ove the vacuum control
switch.
5. R em ove the control cables and tra n sfer them to the
replacem en t control unit. Check them fo r adjustment.
Installation
1. Attach the blow er switch to the unit. Connect the
harness connector and illum inating lam ps. Attach
the mounting bracket. Install the vacuum switch and
hoses.
2. L ift the unit into position and attach it to the dash.
3. Connect the battery ground cable.
BLOWER M O TO R SWITCH (Fig. 4 4 )
Removal
1. Disconnect battery ground cable.
2. Disconnect
w iring harness connector at blow er
switch.
3. R em ove blow er switch mounting screw s and rem ove
switch.
Installation
1. P la c e b low er switch in position and install mounting
screw s.
2. Connect w irin g harness to switch.
3. Connect battery ground cable.
BLOWER M O TO R RELAY (Fig. 4 4 )
Removal
1. Disconnect w iring harness at re la y connector.
2. Rem ove the re la y mounting screw s and rem ove
relay.
Installation
1. P la c e re la y in position and d riv e mounting screw s.
2. Connect w iring harness to relay.
CHEVROLET TRUCK SERVICE MANUAL